kasetsart journal natural science

Kasetsart J. (Nat. Sci.) 40 : 26 - 32 (2006)
Seed Development and Maturation of Eryngo (Eryngium foetidum L.)
ABSTRACT
Boonsong Ekpong 1 and Sutevee Sukprakarn 2 *
Flowering pattern and seed development were studied in two eryngo accessions (EF006 and
EF007) to determine the optimum time of harvest for seed production. Flowering peak was 117 days
after transplanting (35.6 umbel heads) and 121 days after transplanting (38.7 umbel heads) in EF006
and EF007 accessions, respectively. Seed in both accessions reached their physiological maturity 40
days after anthesis, with 93.75-95.75% germination when the seed head had just begun to turn brownish
black in color. Shattering, however, commenced 65 days after anthesis.
Key word: seed development, optimum harvest time, seed germination
INTRODUCTION
Seed crops must be harvested when seed
quality is at maximum. Some physiological
markers have been used in order to identify the
time of maximum seed quality. Harrington (1972)
proposed the hypothesis that maximum seed
quality was achieved when seeds reached
maximum dry weight at the end of the seed filling
period. This hypothesis has been supported by
results in Zinnia violacea Cav. (Miyajima, 1997),
Brassica napus L. (Still and Bradford, 1998) and
Daucus carota L. (Nascimento et al., 2003).
Seed maturity effects on seed quality are
particularly evident in indeterminate crops. For
example, flowering in carrots progresses from the
1 st umbel to the 2 nd and 3 rd umbels during
reproductive development (Oliva et al., 1988). In
these cases, the effects of maturity on seed quality
are exacerbated by the fact that these crops exhibit
shattering (or shedding) of seeds as they mature.
Thus, delaying harvest to allow later developing
seeds to mature risks losing mature seeds to
shattering. On the other hand, early harvesting
results in more poor quality immature seeds that
may be difficult to remove by standard cleaning
and grading techniques (Bradford, 2004).
Eryngo (Eryngium foetidum L.) is known
to be a native of Central and Latin America, from
southern Mexico to Panama through Brazil and
from Cuba to Trinidad. It was introduced into
South-East Asia by the Chinese as a substitute for
coriander. It is an aromatic plant which is usually
grown as a leafy vegetable used as a seasoning
and for medicinal purpose in various countries
such as Vietnam, India and in the Amazon region
(De Guzmao et al., 2002).
The effect of umbel head maturity at
harvest on seed quality has not been reported for
eryngo. This information is needed to determine
the stage of harvest attaining maximum
germination and vigor. Therefore, the objective of
this work was to determine the physiological
changes during seed development and correlated
them with visual indicators to determine optimum
harvest time.
1 Faculty of Agriculture, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand.
2 Department of Horticulture, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.
* Corresponding author, e-mail: agrsts@ku.a.c.th
Received date : 0709/05 Accepted date : 30/01/06